how much horse power gains for these mods

Zinc03GT said:
I would say skip the cai and get a maf, go throttle body & plenum...you could see close to 20

20 with just a T/B and PLENUM????? uh uh... His car already has an 80mm MAF. I wouldn't change that unless he got larger injectors.. T/B and PLENUM 7-12 as a paired unit.. I agree on the CAI, not much improvement that I can feel, if any at all..
 
pony_vert02 said:
20 with just a T/B and PLENUM????? uh uh... His car already has an 80mm MAF. I wouldn't change that unless he got larger injectors.. T/B and PLENUM 7-12 as a paired unit.. I agree on the CAI, not much improvement that I can feel, if any at all..

I was including the x-pipe and cat-back from the original post...sorry for the confusion
 
If you go on SLP's sight they have dyno results showing a gain of about 30 rwhp for the headers/x-pipe/catback (260 rwhp total). So I would estimate about 15-20 rwhp for the x-pipe & catback without the headers. As far as the t/b & cai. You'll get some more gains but not huge. Maybe another 3-5 rwhp.

Overall 20 is a pretty good guesstimate I'd say.
 
DeathWish said:
I am thinking about adding some mods, and would like to know the ranges for HP gains...

1) Mac Cold Air Intake
2) 10mm throttle body upgrade
3) SLP Loudmouth Exhaust
4) SLP X-PIPE with high-flow cat

thanks.

OK...let me chime in hear...

1. Depends on what you are comparing it to. Compared to stock +5 hp
Compared to K&N, snorkel off, nothing. To all those that say CAI's are worth
nothing--when compared to the stock system with the paper filter they will get you about 5hp. How can the K&N with a removed snorkel yield about 5hp (dyno proven countless times) and a CAI nothing? The CAI's use a K&N or equivalent filter!! Now if you're talking about a kit such as a FIPK then maybe slightly more because of the MAF to TB pipe which is restrictive.

2. I have yet to see a larger TB dyno more horsepower. Funny how every plenum test is the 70mm vs the 75mm. The Modulardepot plenum test shows lower hp and tq readings with the 75mm. I wonder how the 65mm would do. hmmm...

3. Exhaust. Saying this won't yield gains has got to be the biggest myth going. Any aftermarket muffler that is straight through such as magnaflow or borla will yield a minimum 5 rwhp gain. I believe the stock mufflers are chambered which don't flow nearly as well as the straight through. I believe magnaflow has an article where they welded in mufflers (on a cobra) and gained some nice hp. 5.0 magazine did a test comparing mufflers and noise levels. Basically, magnaflow and borla gave the best gains while being the quietest. If you search the net, you will find these articles.

4. The rule is that 1 cat will suck 10hp on a 300hp motor. So on a 260hp motor with 2 cats per side you're talking about 8.5 per side or 4.25 per cat.
So if you go to a 2-cat X-pipe you will add about 8.5hp rwhp. My car dynoed 237rwhp and then 252 with just the addition of pullies and a magnaflow 2-cat x-pipe. Based on what I've seen, I was estimating 6rwhp
from the pullies which would leave about 9 from the x-pipe. Hmmm, kind of adds up.

Say 18-20rwhp.

Hope this helps. :flag:
 
With all that $$$ your spending, get you a set of gears, get a good shop to install them, get a chip to recalibrate everything, bump your timing with the chip, and get you a set of mufflers your choise to weld into the car. You dont need an entire catback imo. Most simply get it for looks and sound since some are stainless. With gears, welded in mufflers, and the chip, you are looking close to $800 which is less than what your looking to spend anyways. You will notice a TON more kick in the pants and you will have a decent sound as well. Hell you could probably have enough money left over to get you a decent mid pipe as well.

Id say CAI $180
TB $200 for an ok one
Most catbacks are what like $350-$450 something like that
Hi flow catted mid is at least $350.
o/r pipe is about $150

Minimum your looking at $900 before anything is installed. All that you can do yourself though. If you get a mid with cats your looking in the area of $1100 before install.